Snap-action switch



Sept. 19, 1961 w. L. CHERRY, JR

SNAP-ACTION SWITCH Filed Aug. 5, 1959 an a w I 0 l 9 3 -1: 4 I: h

w i Q United States Patent 3,001,042 SNAP-ACTION SWITCH Walter L.Cherry, Jr., Highland Park, 111., assignor to Cherry Electrical ProductsCorp Highland Park, 11]., a corporation of Illinois Filed Aug. 3, 1959,Ser. No. 831,142

4 Claims. (Cl. 200-67) My invention relates to a new and usefulimprovement in a snap-action switch and more particularly to an electricswitch having a switch blade movable with a snapaction between movingactuating contact blades.

Another object of my invention is in the provision a switch of thischaracter of a snap-action switch blade which by reason of its operativeconnection with an actuating means is prevented from accidentallyreaching and maintaining an idle position.

0 Yet another object of my invention is in the provision in a switch ofthis character which is of a rigid and sturdy construction, which iscompact, simple and economical in manufacture.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of partsto be hereinafter described and claimed. t

The invention will be best understood by reference to the accompanyingdrawings showing the preferred form of construction, and in which:

FIG. 1 is an elevational view of my snap-action switch with the coverremoved showing the parts thereof in normal position;

; FIG. 2 is an elevational view similar to FIG. 1 but showing the partsin operative position;

FIG. 3 is a perspective view of the parts of my improved snap-actionswitch in exploded relation; and

FIG. 4 is a schematic view showing progressively the positions of themovable parts of my snap-action switch as they move from their normalposition to their actuated position.

A housing is indicated as at 10. It consists of a back wall 11, sidewalls 12 and 13, a top wall 14 and a bottom Wall 15. A cover 16 isadapted to be mounted on the open side of the housing and fastened byscrews or the like 17 passing through holes 17 and 18 formed in thehousing 10 and cover 16 respectively.

The side wall 12 is provided with a plurality of vertically alignedslots 19, 20 and 21. Each of these slots has open communication with acavity 22 formed internally in the housing 10.

In the uppermost slot 19 there is fixedly positioned a contact bearingmember 23. Likewise in the lowermost slot 21 there is fixedly positioneda contact bearing member 24. The inner ends of the members 23 and 24disposed in the cavity 22 are movably connected together by a bar 25.The means for connecting the bar 25 to the ends of the members 23 and 24consists of lateral projections 26 and 27 extending parallel to thelongitudinal length of the bar 25 and which are insertable intoapertures 28 and 29 formed in the ends of the contact bearing members 23and 24 respectively.

In slot 20 there is fixedly positioned a movable switch blade 30. Thisswitch blade 30 has a longitudinal length less than the contact bearingmembers 23 and 24 so that its end 31 disposed within the cavity 22 isspaced from the bar 25 as seen in FIGS. 1 and 2.

A mounting post 32 frictionally fits within the cavity 22 in facialabutment with the inner face of the side wall 13. This mounting post 32supports a yieldable support element 33. This support element 33 has itslowermost end 34 bent in the direction of the bar 25 as seen in FIGS. 1and 2. Between the end 34 of the support element 33 and the end 31 ofthe switch blade 30 is a substantially rigid actuating link 35.

This actuating link 35 is of a U-shaped formation. The bar 25 is adaptedto be disposed between the arms 36 and 37 of thelink 35 as seen in FIGS.1 and 2. The free ends of the arms 36 and 37 are V-notched as at 38. Thebase of the bight portion of the link 35 is likewise V-notched. The freeend 31 of the switch blade 30 as well as the end 34 of the supportelement 33 are positioned in the V- notches.

A plunger 39 is slidably carried by a guide block 40 connected withinthe cavity 22 by means of a screw (not shown) which is threaded throughan aperture 41 formed in back wall 11 and into a threaded aperture 42formed in the block 40.. The plunger 39 has an enlarged head 43 adaptedto be in facial engagement with the top surface of the contact bearingmember 23. In the normal position of the parts of the switch heretoforedescribed such contact bearing member 23 will position the plunger 39 soas to expose one end 44 thereof through an aperture 45 formed in the topwall 14 of the housing 10'.

Between the contact bearing member 23 and the movable switch bladeintermediate the ends thereof is a non-conductive stud 46. This stud 46is fixedly carried by the contact bearing member 23 as is seen in FIGS.1, 2 and 3.

In the installation of the parts within the housing 10 the contactbearing member 24 is formed so that its innermost end has a siight risethereto in the direction of the free end 34 of the support element 33.By such arrangement the. contact bearing member 23 through the bar 25 isyieldably maintained in bearing relationship with the enlarged head 43of the plunger 39.

As will be noted from FIGS. 1 and 2 the actuating link 35 is of a lengthgreater than the normal distance between the end-3'1 of the switch blade30 and the end 34 of the support element 33. By reason thereof when theparts are assembled the switch blade 30 is bent upwardly so that theuppermost contact 47 thereon is in engagement With contact 48 of thecontact bearing member 23.

When an applied force is placed on the free end 44 of the plunger 39 itwill cause a simultaneous downward movement through bar 25 of thecontact bearing members 23 and 24. The downward movement of the contactbearing member 23 together with the stud 46 mounted thereon will causethe switch blade 30 to be deformed into a substantial S-shaped formationas shown in sketch B of FIG. 4. The free end 31 of the switch blade 30is forced in a downward direction by the contact 48 of the contactbearing member 23. The bar 25 is freely movable transversely withrespect to the actuating link 35. As the switch blade 30 is forced tomove downwardly below its normal horizontal plane it will yieldably movethe actuating link 35 against the support element 33 causing the same toyieldably move in the direction toward the supporting post 32. Bycontinued downward movement of the free end 31 of the switch blade 30,the inherent resiliency of the support element 33 will overcome theforce, transmitted to it through the actuating link 35 that has causedit to move in the direction of the supporting post 32, and will forcewith a snap-action the end 31 of the switch blade 30 in a downwarddirection until the lower contact 47 thereof engages the contact 49 ofthe contact bearing member 24. Because of this resilient force of thesupporting element 33 acting upon the actuating link 35 it will causethe link 35 to be reversely tilted into the position shown in FIG. 2,which tilting results in the snap-action movement of the end 31 of theswitch blade 30 into its operative position. When the applied force isremoved from the plunger 39 the reverse action will take place by reasonof the resiliency of the contact bearing member 24 which has been placedin a stressed position below its normal longitudinal plane by the abovedescribed movement of parts which resulted in the snapaction of theswitch blade 30.

The stud 46 carried by the contact bearing member 23 when moved intoengagement with the switch blade 30 bends the same downwardly from apoint distant from its fixed base, deforming its normal longitudinalplane and thereby cooperating with the contact 48 of the contact bearingmember 23 and link 55 to deform the switch blade 36 into a substantiallyS-s'haped formation. Because the stud 46 moves with the contact bearingmember 23 and operates upon the switch blade 30' as above described itprevents the switch blade 30 from reaching an idle position which wouldbe a substantially horizontal plane through the longitudinal length ofthe switch blade 30, the longitudinal length of the actuating link 35,and the end 34 of the supporting element 33.

It should be noted that before the snapaction movement of the blade Sitin either direction, the contact heating force between its contact 47and the moving contact which could be either of the contacts 48 or 49,is maintained.

While I have illustrated and described the preferred form ofconstruction for carrying my invention into effect, this is capable ofvariation and modification without departing from the spirit of theinvention. 1, therefore, do not wish to be limited to the precisedetails of construction set forth, but desire to avail myself of suchvariations and modifications as come within the scope of the appendedclaims.

Having thus described my invention, what I claim as new and desire toprotect by Letters Patent is:

1. A snap-action switch comprising a pair of parallelly extending spacedapart contact-bearing members, an element providing connection betweencorresponding end portions of said contact-bearing members, a switchblade positioned between said contact-bearing members in spaced relationwith respect thereto and having a contact engageable with the contactsof said contact bearing members, means carried by one of saidcontact-bearing members and engaging said switch blade to impart flexingof said switch blade upon flexing of said contact-bearing members, asupporting member extending in a vertical plane with respect to saidcontact-bearing members and having an end portion angled in a directiontoward the contact-bearing end portion of said switch blade, asubstantially rigid link connecting said angled end portion and saidcontact-bearing end portion of said switch blade and of a length greaterthan the distance between said angled end portion and the said end ofsaid switch blade so as to effect snap-action of said switch blade ineither direction past its long axis, a fixed mounting for correspondingends of said contact-bearing members and an adjacent end portion of saidswitch blade, said switch blade engaging means when forced against saidswitch blade adapted to deform said switch blade in the direction of itslength so as to cooperate with said link to effect a snap actionmovement of the switch blade on either side of its said long axis, andan actuating member for said contact-bearing members.

2. The device as defined in claim 1 in which the supporting member isyieldable and acts upon the link in a direction against the movement ofthe switch blade to effect said snap action movement of said switchblade when said contact members are moved by said actuating member.

3. The device as defined in claim 1 in which the said means engages saidswitch blade at a point spaced from the point of engagement between theswitch blade and said link.

4. The device as defined in claim 2 in which the said means engages saidswitch blade at a point spaced from the point of engagement between theswitch blade and said link.

References Cited in the file of this patent UNITED STATES PATENTS1,995,877 Woodworth Mar. 26, 1935 2,574,429 Wood Nov. 6, 1951 2,748,215Davis May 29, 1956 2,870,282 Brand I an. 20, 1959

